Fix translation of interface with non-abstract methods in JS BE

Fix additional case of generic interfaces in KT-18187

compiler/testData/codegen/box/traits/interfaceWithNonAbstractFunIndirect.kt

@@ -20,7 +20,7 @@ fun box(): String {
     if (bar1 != "bar:default") return "fail2: $bar1"
 
     val bar2 = A().bar("q")
-    if (bar2 != "bar:q") return "fail3: $bar1"
+    if (bar2 != "bar:q") return "fail3: $bar2"
 
     val foo2 = B().foo()
     if (foo2 != "foo") return "fail4: $foo2"